I've got a Cooler Master 690 II Advanced case that has 3 of the 140mm 1000 rpm fans, and they are the quietest fans in the case, most 120mm fans are louder. One thing that has the potential to make even a quiet fan loud is by having a restrictive fan grill, this will cause turbulence and cavitation which will create extra noise.

Yes, I'd say. Too good to be true. Only 1000RPM, to provide 69 CFMs at 16db? They would sell for triple of what they're selling for IMHO. Anyway, I have to personal experience on these. Next order I could try one.
They can be PMed for pretty cheap!